Plasma Panel suddenly slow and sluggish responsiveness after update to 6.7.4

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1

kinfo
Operating System: Arch Linux
KDE Plasma Version: 6.7.4
KDE Frameworks Version: 6.29.0
Qt Version: 6.11.2
Kernel Version: 7.1.6-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 7900X 12-Core Processor
Memory: 128 GiB of RAM (124.9 GiB usable)
Graphics Processor 1: AMD Radeon RX 7600
Graphics Processor 2: AMD Ryzen 9 7900X 12-Core Processor

The panel and launcher menu have suddenly gotten very slow to response.

When I click on my panel icons in the upper left hand corner, nothing happens.

Everything is frozen for almost 10 seconds. And then the system slowly responds with whatever I clicked on.

This also happens when I try to change virtual desktops.

Before my upgrade this problem did not exist.

Everything was working fine before.

Also when I set shortcut keys to change the virtual desktops, that seems to work faster than using the mouse and panel interaction with the pager/virtual desktop space.

Any thoughts ?

2

look at ksystemlog and see if you tell what is causing the lag.

i assume you have tried rebooting, but have you tried rebooting to an empty session?

settings > desktop session > start with an empty session

3

I did not have ksystemlog installed. I did that with pacman -S and now installed but I don’t have log records for last night when it was happening.

This morning I rebooted and restarted with an empty session.

Waiting for further results.
Will update in a few days.

Thank you for your reply.

Very frustrating I might add.

It was working so well with 8 virtual desktops and over 20 different windows and apps and then cough sooooo sllllooooowwwwww

4

in the meantime what does swapon say if you type that into a terminal?

you are might still be running out of ram even with 128GB with 8 VM’s going.

5

]$ swapon
NAME TYPE SIZE USED PRIO
/dev/zram0 partition 4G 0B 100

I have btop showing RAM usage around 60 GB. Never above 90 GB.
Also I had 2 VM’s running last night each 32 GB (Windows 10 and Arch linux).
CPU usage was fine.

Everything now shut down as per your suggestion of starting with an empty session.

Keep you posted.
Thanks again.
I appreciate it.

6

relying on zram for swap when using a ton of VM’s might not be the best tactic.

and 4GB is nothing considering what you are attempting.

i would at least create a decent swapfile (12GB?) to go along with it and make them both priority -1 to let the system decide which is best.

7

I typically use only 2 VM’s each 32 GB.
VM Arch linux is dynamic usage whereas
VM Windows 10 is always 32 GB.

I also have 8 virtual desktops running with around 20 apps (GIMP, LibreOffice, Firefox (20 tabs), VLC, Kitty Neovim.
Never had problems with using the above with 128 GB until last night.

You suggest that I should increase swapfile usage to 12 GB ?
I can safely allocate about 25 GB.

Should I do that (25 GB ) ?

8

i’m suggesting keeping the zram where it is, but ADDING a swapfile in addition to zram.

relying completely on zram might be part of your issue.

9

I don’t know much about zram and swapfiles.
Let me do some research on that.
I assume I can do that from the terminal and reboot ?

10

https://linuxize.com/post/create-a-linux-swap-file/

11

Thanks.
I did some research and setup the following:
I changed zram to 24G with priority 100.
(Had some issues with the zram config file memory units).
I added a swap file of 16GB in the fstab with priority 10.

zramctl:
NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 zstd 24G 4K 64B 20K [SWAP]

swapon --show
NAME TYPE SIZE USED PRIO
/swap/swapfile file 16G 0B 10
/dev/zram0 partition 24G 0B 100

Then I setup a kitty terminal to watch si/so for vmstat 1.
When/If it gets sluggish again, I am to watch the si/so columns in vmstat 1.
If they remain same, then the problem is not my system but something with
KWin and Plasmashell GPU related.

Does this sound reasonable ?

12

Should i change swappiness from 60 (default) to 100 ?

sudo sysctl vm.swappiness=100 ?

13

This is not the thing to do, as zram will first get filled up and then the swapfile will be constantly used. It would be better to setup zswap. This article explains the differences between zram and zswap, and why zram only makes sense when you don’t have any disk-backed swap.

Also, in this case, zram probably wouldn’t make much of a difference. I have used on low-power SBCs without it having much of an impact on system performance.

14

i would have changed them both to priority -1 and let the system sort it

i would also not change the swappiness value

15

Thanks for your replies and assistance.
I will mark your reply with the URL as solution.

16

I went to your linked article, way above my head.
:slight_smile:

I’ve never heard of zswap.
Should I create a zswap instead of my current setup listed above ?
(I have 128 GB Ram , upper usage limit is ~70 GB).

17

good point, i didn’t even clock the difference between zram and zswap because it showed up as swap space using swapon

regardless, i think having a physical swap file or swap partition is always the best practice.

18

Zswap works at another layer than zram, transparently and before disk swap, so there is no specific thing to “swapon”. You need to add zswap.enabled=1 to your Linux kernel command line.

I also use Arch Linux, with systemd-bootd/gummiboot, so it has to be added to the conf files under /boot/loader/entries, at the end of the lines starting with options. I have the following command line for zswap, which works fine with my 16 GiB of RAM:

zswap.enabled=1 zswap.max_pool_percent=80 zswap.compressor=zstd zswap.shrinker_enabled=1

You would then disable zram (and make sure that it doesn’t set itself up again on the next reboot) before restarting to enable zswap. If you use grub as bootloader, I can also help you.

Yes, having a swap file or partition is never a bad thing, except if you are limited by disk bandwidth or use devices which have limited write endurance.

19

I am using GRUB with Archlinux.
I am also using 128 GB of RAM .
How should I go about setting up zswap ?
Does it use RAM or disk ?
Also I do not have your gummiboot.
Not sure what that is all about.

I can research the finer points.
If you can give me some help , would be appreciated

20

i think the easiest thing to do is just disable zram and make sure it doesn’t come back.

check the wiki